Center-clamp plate for record matrices



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CENTER CLAMP PLATE FOR RECORD MATRICES.

APPLICATION FILE APR. 4. 1921.

ill-ID osmosis r. BOWMAN, on ceases, NEW GNGRS so snip Davis.

TEEZ -CLAMIP PEBA'TIE FQR RECORD MATRECES.

Application file-i April 6,

To all whom it may concern:

Be ii; known that we, Gnome liownnrr in clamping matrices for making talking machine records in place on the presses customarily employed, i has been found necessary so clamp the matrices adjacent th ir centers, as well as about their outer edges, owing to the thin metal from which the matrices are formed and the necessity for providing a central hole in the records. Clamps employed for holding the atrix eel. in place must, however, not only be permanently rigid and unmoving under the enacting conditions or" repeated use, but must also he so formed and constructed that they will produce a pleasing contour to the surface of the record with which they come in conlcac. Clamps heretofore used have been clclicieni, in these particulars, having a ienil ency shii's slightly after being used for some time loosening'thereby their grip on the matrix and producing eithef an unrlue "epressiou or an unsightly elevation in the record. An object. of our invention is to provide a clamp which will remain rigidly in position, and which will materially improve the appearance of records.

Another obgect is to provide a center clamp of "chis type which may be'more readily and rapidly fixed in position and removed, reducing materially the lalgor cost incident to changing matrices, without sacrificing the permanent rigidity of the clarnp when in position. p

ii; 15 i tanti'zo reg ster each matrix accurately we to the center of the press heail on which it is mount-eel. Owing to the cliiiiculties incident to the construction of ris which woulo.

Specification of Letters Patent.

2 record matrix to the ieacl of t is press.

Patented Jan. 3,,3922

1921.. Serial No. 458,693.

engaging its periphery, such as bhe usual clamping ring overlying the outer edge of the matrix when positioned on the press. 'l'he sluhculty in registering matrices by or gugernent therewith adjacent their centers has been caused partly by the thinness ofmetal from which the matrices are .iornieo, increusingthe liability of crumpnng the edges or a matrix engaging a central registeringdevice, and also by the necessity for employing a clamp which will nor; only he lo uteri accurately at the center 01 the matrix, but which may also be centered properly in the press head Withouc so Light an engagement as to preclude the release of the clamp within a reasonable length of time. An object of our invention is to provide a central clamp which will register the matrix accurately at the center of the press heafi, and which may at the same time be readily and rapidly applied and removed withous slicrificing its registration accuracy.

Other objects and advantages of our in wention will be apparent from the following (lescription. taken in connection with she accompanying drawings, in which:

Fig. l is a somewhat cliagrernmsaic si elevation of the hezuls of o press, pa

c is being broken away to show the pressing plates in transvrse secsion,

and ls may be of any approved construc tion, those shown being of the type disclosed in our cop'eniling application Serial No. 458,80 filed April 192i.- Eech of the places 11 and is is prcvirlezl with the usual uch is placed a The plates 11- Fig, 2 is a top plan View of a portion oi?- ice lace-or one of the pressing plates, pares We hold the central portion of the matrix 17 inplace by a center clamping plate 19,

circular inform. The plate 19 is provided.

with a cylindrical body portion 20 fitting accurately and snugly in a central aperture in matrix 17 and where a bed plate 16 is employed, preferably fitting also a corresponding aperture in said plate. The center plate 19 also is provided with a narrow bevelled lip 21 of just sufficient extent to overlie and engage the inner edge of the matrix 17 to retain it in position.

In order to register matrix 17 accurately on the pressing plate 11, we provide said plate with a socket engaged by a registering portion of the clamping plate 19, so that said clamp plate and presser plate will he maintained inaccurate fixed relation. We have found it convenient for. this purpose to extend the body 20 of clamp plate 19 slightly below the surface of the-table 15 into an annular recess 22 formed in said table and fitting accurately against the edges of the center plate 19. With this construction it will be evident that the matrix when placed on the table'may be rapidly registeredf with complete accuracy thereon by passing thebody 20 of center plate 19 through the central aperture of the matrix and into recess 22 in table 15.

We employ suitable. means for holding plate 19 in clamping position, one object as above noted being to provide for ready release and engagement of said clamping means. We have accomplished this object by mounting on the plate 19-one or more clamp rods 23, the form illustrated in the upper part of Fig. 3 having two of these rods, which pass upward through suitable recesses in resser plate 11 and the press head 10, having suitable knurled nuts 2.4

at their upper ends en aging the top of the press head 10. By re ying upon socket 22 in the presser plate for registration of the clamping plate 19, we are enabled to avoid the necessity for having rods 23 or their equivalentsfit snugly injthe corresponding recesses in plate 11 and head 10, as would be necessary were such recesses relied on to register the clamping plate. The relatively loose fit of rods 23 in these recesses therefore permits the plate to be readily and rapidly released by removing the nuts 24:, and to be replaced withcorresponding accuracy. Furthermore, the danger of destroying accurate registration through wear of the parts is reduced to a minimum, since there is practically no rubbing or sliding between the parts which insure registration during the application or removal of the center plate.

Obviously the type of socket in the table 15, and the corresponding contour of the engaging element on plate 19 may be varied head 13. Furthermore, pin 26 a may menace considerably; and furthermore, the precise construction and arrangement of the bolt rods 23 may he likewise altered. -We particularly desire, however, to avoid the previous construction, in which the clamping plate was held in position by threaded means located so far below the press head that such means was relatively inaccessible and could only be removed. with consider able difficulty, ordinarily by extending a long screw river into a relatively small hole in the press head..-

In order to form the usual. central hole in the record, we term the upper clamp plate Illlwith a central aperture 25 registering with a correspondin aperture 26 in the presser plate ll, an mount at the center or" the lower clamp plate 19 a cooperating stud 26 which passes into the aperture 25 when the press is closed. We prefer to mount pin 26 in fixed position, and to taper it slightly, so that the record may he readily slipped up over the pin alter pressing. We may also employ pin 26 asthe means for holding the lower clamping plate 19 in position. This is accomplished readily hy re ducing the diameter of the pin 26 at its lipase to form a shoulder .27 overlying and engaging the lower plate 19, and threading the extension 280E pin 26 below the shoulder into a bore 2%) in the lower presser it. With this construction the pin and lower clamping plate 19 may be readily removed I lower clamping plate 19 may he held in position icy means similar to that illustrated in connection with the upper clamping plate, suitable changes being made iii necessary to adapt the construction to the lower preps e mounted in a variety of ways. We ve, however, found that the construction illus trated is cheap to produce, rapid to remove and replace, and is not likely to get out or" order in use.

While we have shown our invention as applied to a common lrirnigd of press, obviously it may be employed on ther types. in particular, our invention is not restricted to presses in which a detachable pressing plate is em loyed, as obviously the clamping plate e installed on a press having a solid head. a

We claim: i

l. A matrix center clamp, including a matrix engaging nieinher, and means directly release in from the outside of the press or con- I head for locking said member in clamping position.

2. A matrix center clamp, including a matrix engaging member, an extension on said member projecting into the press head, and means releasable from the outside of the press engaging said extension and the press head to hold the member in clamping position.

3. A matrix center clamp, including a matrix engaging member, a rod connected to said member and extending through the press head to the outside, and releasable means engaging the outer end of the rod and the press head for iocking said member in clamping position. i

4. A matrix center clamp, including a matrix engaging member, a rod rigidly mounted on said member and extending through the press head to the outside, and a nut threaded on the outer end of the rod adapted to engage said head.

5. In a record press, a matrix table having a socket therein, a matrix center clamp adapted to fit accurately into said socket to register a matrix accurately on the table, and means for locking said clamp in operative position.

6. In a record press, a matrix table having a socket therein, a matrix center cilamp' adapted to engage the e ges of a central aperture in a matrix and to fit accurately into said socket to register the matrix accurately on the; table, and means for locking said clamp in operative osition.

7. In a rehord press, a matrix table having a socket therein, a matrix center clamp including a circular disk adapted to engage the edges of a central aperture in matrix and provided with a chimping flange overlying the matrix adjacent said edges, said disk being adapted to fit accurately in the socket to register said matrix on the table, and means for locking the disk in clamping position.

8. In a record press, a matrix table having a socket therein, a matrix center clamp adapted to engage the edges oi a centrai aperture in a matrix and to fit accurately into said socket to register the matrix accurately on the table, and means for locking said clamp in operative position, said locking means including an extension fitting loosely in a bore in the press head and extending to the outside of said head, and a releasable locking element engaging the outer end of said extension and said head.

9. A record press including a. matrix table having a central annular socket; amatrix clamping disk adapted to engage the edges of a central opening in a matrix and provided with a marginal flange adapted to engage the matrix adjacent said. edges, the disk fitting accurately in said socket to register the matrix on the table, a rod mounted on the disk and extending freely through a bore in the press head to the outside thereof, and a clamping nut threaded on the end of the rod adapted to engage said head.

Signed at Orange in the county of Essex, and State of New Jersey, this 31st day of March, D. 1921.

GEORGE HOWLETT CHARLES Ci. BUWMAN.

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